Jet Set Willy is a computer game originally written for the ZX Spectrum home computer. It was published in 1984 by Software Projects and ported to most home computers of the time. The game is a sequel to Manic Miner (1983), and is the second game in the Miner Willy Series. It was a significant development in the platform game genre on the home micro.
Jet Set Willy is a flip-screen platform game in which the player moves the protagonist, Willy, from room to room in his mansion collecting objects. The game is an early example of a nonlinear title since, unlike the screen-by-screen style of its prequel, the player can explore the mansion at will. Willy is controlled using only left, right and jump. He can climb stairs by walking into them (jumping through them to avoid them) and climb swinging ropes by pushing left or right depending on what direction the rope is swinging. The play area itself consists of 60 screens making up the mansion and its grounds and contains hazards (static killer objects), guardians (killer monsters which move along predetermined paths), various platforms and collectable objects. The collectable items glow to distinguish them from other items in the room.
Willy loses a life if he touches an enemy or falls too far, and he is returned to the point at which he entered the room. This may lead to a game-ending situation in which Willy repeatedly falls from a height, losing all lives in succession.
Music on the Spectrum version was Beethoven's Moonlight Sonata for the menu, and If I Were a Rich Man during the game itself.